大断面吊平顶隧道窑焙烧原理上的探讨和建议(一)

本文通过对原材料烧结特性的分析 ,提出了制定合理的焙烧曲线在窑炉结构设计和操作控制中的重要性。特别是对煤矸石、粉煤灰为主要原材料的空心砖坯体在焙烧过程中的传热机理进行了叙述。本文中提出了在大断面隧道窑焙烧过程中气体流动的“穿流”与“环流”的概念。这也涉及到码坯的型式、边隙和顶隙的大小、产品的形状和孔洞率、原材料的烧结性能及窑炉的密封性等因素。从产品质量的角度出发 ,提出了在坯体出现软 (玻 )化前 ,坯体中的可挥发组分和可燃物应基本挥发完毕或是完成燃烧。在窑炉的预热带对含热量较高的坯体应增设循环系统限制坯体的燃烧速度 ,稳定焙烧带的位置 ,提高预热带车面温度等建议。

The paper points to work out a reasonable firing curve to be importance for tunnel kiln structure designing. The heat transmission mechanisms are different from traditional tunnel kiln during firing, special for coal gangue and fly ash bodies. For this reason, the article raises the conception of 'Through flow' and 'Peripheral flow' of air flow during firing in the large cross-section tunnel kiln. It involves also the setting patterns, the edge gap and top gap of varying sizes, product's forms and perforations, the sintering characteristics of raw materials and kiln's sealing, etc. The article points that volatility gases and combustibility materials in the green brick bodies should be completed volatilng and burnout before brick bodies softening (liquid phase), in order to obtain good quility products. The author suggests to increase circulation systems in the preheating zone so that controls the speed of combustibiling of high calorific value bodies and stabilizes the position of the firing zone and improves the temperature of setting pack bottom on the kiln car, and so on.